Flexure spring punch



Aug. 18, 1964 A. SCHULMAN 3,144,988

FLEXURE SPRING PUNCH Filed May 11, 1962 A TOANEX United States Patent SPRING PUNCH David A. fichulman, Brooklyn, NJEL, assignor to Sperry Rand Qorporation, New York, NFL, a corporation of Delaware Filed May 11, 1962, Ser. No. 193$5d 6 tlllaims. (til. 23 t-lll9) The invention relates to the field of punches. More particularly, it relates to a novel punch suitable, for example, for preparing punched cards or punched tapes.

The punch which is described hereinbelow is characterized by the fact that it is extremely low in cost because of its simple construction using a minimum of parts. By virtue of its construction the punch is inherently very reliable since there are less parts to malfunction and also there are only a few wear points. Further, the punch of this invention has low power input requirements due to low inertia loads and to the fact that aside rom minor system losses as a result of friction, etc. all energy delivered to the system and not expended in actual punchin is retained in the system. Finally, the punch of this invention is capable of operating at extremely high speeds, eliminates the need for a punch clutch arrangement, and yet will operate at these high speeds at a low noise level.

Accordingly, it is an object of this invention to provide a punch arrangement having relatively few moving parts.

It is a further object of this invention to provide a high speed punch, which can operate at a low noise level.

A still further object of this invention is to provide a high speed punch having low power input requirements.

Other and further objects and advantages of the invention will become clear when the following description is read in conjunction with the accompanying drawing. The scope of the invention will be pointed out with particularity in the appended claims.

Briefly stated, in accordance with this invention there is provided a punch which includes a punching member fixed to a spring which in turn is supported at one end by any suitable mount or frame. The other end of the spring is normally held by a latch which is releasable by electromagnetic means. While the latch is in place the punching member is prevented from passing through a record medium which is moved proximately thereto. When the latch is released, the spring bearing the punching memer is solely under the control of the profile of a continuously rotating cam. During a portion of each cycle of cam rotation an abrupt low radius portion of the cam profile frees the spring to drive the punch member through the record medium.

In the drawing:

FIG. 1 is a fragmentary side View partially in section of an embodiment of this invention having a single punch.

FIG. 2 is a fragmentary front View of an embodiment of this invention having a plurality of punches.

Referring now to FIG. 1 a flat spring lltl is provided, fixed at one end to mount if as by a fastener or fasteners Ila. A punch member 12 is attached to spring lltl positioned, as shown, to be normally inoperative to effect a punching operation through a record medium 19. in the embodiment shown, punch member 12 consists of an intermediate link 1?: and punch 14 forming an articulated unit held together by a coupling device 15 which could be a simple pin or a ball and socket joint, etc. Punch 14 may be guided by any suitable means, for example, punch guide 16 to keep the punch perpenicular relative to stripper plate 17 and die 18. A record medium, eg a punch card or tape, is illustrated at 1% and stripper plate 17 and die is have an aperture lhl ldfii l a'tented Aug. 18, 1964 therethrough to permit punch 14 to perforate the record medium when desired.

Spring 10 is maintained in its inoperative or cocked position by latch 2t) which is fastened at one end to a supporter mount 21 by a fastener or fasteners 22. The free end of latch 25 has an ear 23 cooperating with an extension 24 of spring 10 to effect the latching operation. Latch Ztl is normally held in position to block spring 10, for example, by a spring 25 which may be fixed to any convenient stationary portion of the machine on Which the punch is to be used, as indicated at as. The result achieved by spring 25 could easily be accomplished through other means, as for example, constructing latch Ztl as a self-sprung member.

A cam 27 is provided mounted 011 a shaft indicated at Shaft 28 may be rotatably supported by any portion of the machine of which the punch is a part and driven by any conventional source of power. Cam 27' rotates continuously with shaft 28 and rides against a bearing member or cam follower 29 which in turn is mounted on spring 1 as by a fastener 3t).

As cam 27 rotates with shaft 28 its profile will force spring iii and extension 24 away from latch ear 23 during a portion of a cycle of cam rotation, referred to as the overtravel period and will gradually return extension 2d into contact with latch ear 23 with minimum impact. Bar 23 and extension 24 remain together with substantial force, extension 24 being urged against ear 23 by spring to except during the overtravel period, the time that the profile of cam 27 forces spring ltl downward by its action on bearing member 27.

Electromagnet means 31 mounted proximately to latch 2h by any convenient mounting will, when energized by a signal on lead 32, tend to attract latch 20 to it against the tension of spring 25, (or other restoring means) freeing car 23 from extension 24 of spring it).

In the preferred embodiment, the action of electromagnetic means Zll on latch 20 is ineffective to move the latch unless car 23 and extension 24 have been freed of one another by the overtravel of cam 27 transmitted to spring ill. Thus the only signal timing requirement is that the latch release signal on lead 32- must occur during that portion of the cam cycle when extension 24 is removed from contact with car 23. Spurious signals, therefore, appearing on lead 32 will be ineffective to cause a punching operation if they occur at any time other than that portion of the cam cycle wherein ear 23 is free of extension 24. It will be appreciated that as a result of this design of the profile of cam 27 the power requirements of electromagnet 31 are substantially reduced since it need only overcome the relatively weak opposing force of, for example, spring 25.

When electromagnet 31 is energized at the appropriate point of the cam cycle unlatching spring 10, the spring still cannot force punch 14 through record medium 19 until cam 27 presents its low radius portion to bearing member 29. At this point spring lid is abruptly freed to move at its natural frequency driving punch 14 through medium 19. Punch 14 is initially withdrawn from medium 29 by the return vibratory stroke of spring 14) and this is completed by the cam profile.

For any spring 10 with a given natural frequency of vibration, the profile of cam 27 and its speed of rotation can be selected so that after punch member 14 goes through record medium 19 perforating the medium, cam 2'7 will gently contact bearing member 29 just after spring iii begins its initial return vibration, depressing the spring and withdrawing punch 14 from the medium and through stripper plate 17 as spring 10 is forced away from medium 19.

Extension 24 will physically contact and ride over car 2?: driving latch 20 toward electromagnet 31 to be latched snaecsa for the next operation. The top surface 33 of ear 2? and the bottom surface 34 of arm 24 may be appropriately shaped to facilitate this return of extension 24, as is shown.

It will be appreciated that latch 29 can be shaped to provide increased efiiciency and/ or speed of operation of the punch. For example, a projection 35 may be formed on latch 26 so that when extension 24 is freed from ear 23 during the overtravel period, it will move latch 21] toward electromagnet 31, thus still further reducing the load placed on electromagnet 31 and by virtue of the mechanical action, increasing the speed of the units operation. Further, it will be understood that punch member 12 can be mounted anywhere on spring lltl, either to the left or to the right of cam 27, depending upon the particular application intended, i.e. force desired, permissable length of travel of the punch, etc.

it is clear that this type of punch is particularly suited for use as one of a bank of identical punches. Synchronism of punch operation is assured because all of springs ill which are in the bank will follow the same cam profile to the point of release. Consequently, the timing of the unlatch signal or signals which select one or more punches of the gang of punches to be operated on any one punch operation is not critical as to starting time or duration. All that is required is that the signal energizing the electromagnet associated with each punch to be operative, exist during the time interval when the spring id is overtraveled. Spurious unlatch signals before or after this overtravel period will not cause punchrng.

(Vhile the illustrated embodiment shows a cantilever mounting for spring Ill, other types of energy storage arrangements can be employed. For example, a coil spring could be substituted, mounted to exert force in line with the punch member, etc.

A typical arrangement having a plurality of punches is shown in FIG. 2. In this figure the reference numerals used are the same as those used in FIG. 1 where they refer to the same elements. As is seen a plurality of springs, for example, 12 of which 6 are shown, that, 10b lltlf are provided each with its associated latch Ztla, etc. Each spring has an extension arm 24 etc. cooperating with an ear 23a, etc. (not shown) of its associated latch, and its own electromagnet 33a, etc. Only a single cam is used though, if desired, individual cams having the same profile and mounted on the same shaft could be employed. The operation of the unit shown in FIG. 2 is the same as that shown in FIG. 1 and detailed description is not believed to be required.

Summarizing the above it is seen that the punch of this invention operates on a stored energy principle. The punch member is spring operated and the punch actuating mechanism serves merely to release the energy stored in the spring to permit the spring to drive the punch through the medium to be perforated. Cocking of the spring is accomplished through camming, the entire arrangement resulting in an extremely efficient, high speed, low noise mechanism.

While what has been shown and described is believed to be the best mode, and a preferred embodiment of the invention, modifications and variations may be made therein without departing from the spirit and scope thereof as will be clear to those skilled in the art, and the invention is intended to be limited only by the claims.

What is claimed is:

1. A punch including in combination, a frame, a combined punch actuator and energizer spring fixed to said frame, a latch fixed to said frame and positioned to normally retain said spring cocked, a punch member fixed to said spring, a cam rotatably fixed to said frame, and riding on said spring for a portion of its cycle selectively actuable means mounted on said frame for attracting said latch when actuated, said spring thereafter being solely under the control of said cam profile, and out of 4 contact with said latch, said latch including camming means associated with said spring for affecting passage of said spring beneath said latch and retaining of said spring by said latch after release of said latch by said selectively actuable means.

2. In a machine for producing perforated records, a punch unit including, in combination, a flat spring fixed at one end to said machine, a latch pivotably mounted on said machine having a portion which overrides said spring to normally hold said spring cocked, a punch member mounted on said spring, a shaft rotatably mounted on said machine, a cam fixed to said shaft and rotating therewith, a cam follower fixed to said spring, said cam having a profile which is in contact with said cam follower during a first segment of each cycle of cam rotation and having an abrupt declivity to quickly free said spring from contact with said cam during a second segment of each cycle of cam rotation, said portion of said cam profile which is in contact with said follower being shaped to free said spring from said overriding portion of said latch during a part of said first segment of each cycle of cam rotation, and an electromagnet fixed to said machine and effective when energized to remove said latch from latching interference with said spring when said spring is freed from the override portion of said latch, said latch having a projection thereon positioned behind said override portion to cooperate with said spring to move said latch toward said electromagnet during said part of said first portion of cam rotation when said spring is freed from said overriding portion of said latch whereby to reduce the amount of flux required for said electromagnet to attract said latch.

3. In a machine for preparing perforated records a punch unit including in combination, a flat spring fixed at one end to said machine, punch means fixed to said spring, a latch fixed to said machine and having a portion which overrides said spring to normally maintain said spring cocked, a shaft rotatably mounted to said machine, a cam fixed to said shaft and rotating therewith, a cam follower mounted on said spring, said cam having a profile a first portion of which is in contact with said cam follower during a first segment of each cycle of cam rotation and a second portion of which has an abrupt low radius part to quickly free said cam follower from contact with said cam during a second segment of each cycle of cam rotation, said cam profile which is in contact with said cam follower being shaped to free said spring from contact with said overriding portion of said latch during a part of said first segment of each cycle of cam rotation, said latch having a projection thereon positioned behind said override portion to cooperate with said spring during the time said spring is freed from said overriding portion of said latch to move said latch in one direction, and an electromagnet effective when energized to attract said latch in said one direction during the time said spring is freed from said overriding portion of said latch, said punch means being driven in a punch operation when said latch has been removed from latching interference with said spring when said cam follower is presented with said abrupt low radius part of said cam profile, said first portion of said cam profile being further shaped to contact said spring on its said return travel and return it to the latched position, said spring and said override portion being shaped for camming into latching engagement upon return of the spring.

4. The machine defined in claim 3 wherein said punch means is articulated to accommodate flexing of said spring.

5. The machine defined in claim 4 wherein said articulated punch means includes an intermediate link fixed at one end to said spring and a punch pivotably fixed to the other end of said intermediate link.

6. A record perforating machine including in combination, a cam rotatably mounted on said machine and a plurality of punch units cooperating with said cam, each E4- of said units inciuding a combined punch actuator and energizer spring fixed to said machine, a latch mounted on said machine positioned to normally hold said spring cocked, a punch member mounted on said spring, said cam having a profile which rides on said spring for a portion of each earn cycle, said earn profile further having an abrupt low radius portion to permit said spring to travel at the normal frequency when released by said latch, and electromagnetic means mounted on said machine for releasing said latch when energized, said spring thereafter being solely under the control of said earn profile and out of contact with said latch, including camming means associated with said spring for effecting passage of said spring beneath said latch and retaining of said spring by said latch after release of said latch by said electromagnetic means.

References Eited in the file of this patent UNITED STATES PATENTS 

1. A PUNCH INCLUDING IN COMBINATION, A FRAME, A COMBINED PUNCH ACTUATOR AND ENERGIZER SPRING FIXED TO SAID FRAME, A LATCH FIXED TO SAID FRAME AND POSITIONED TO NORMALLY RETAIN SAID SPRING COCKED, A PUNCH MEMBER FIXED TO SAID SPRING, A CAM ROTATABLY FIXED TO SAID FRAME, AND RIDING ON SAID SPRING FOR A PORTION OF ITS CYCLE SELECTIVELY ACTUABLE MEANS MOUNTED ON SAID FRAME FOR ATTRACTING SAID LATCH WHEN ACTUATED, SAID SPRING THEREAFTER BEING SOLELY UNDER THE CONTROL OF SAID CAM PROFILE, AND OUT OF CONTACT WITH SAID LATCH, SAID LATCH INCLUDING CAMMING MEANS ASSOCIATED WITH SAID SPRING FOR AFFECTING PASSAGE OF SAID SPRING BENEATH SAID LATCH AND RETAINING OF SAID SPRING BY SAID LATCH AFTER RELEASE OF SAID LATCH BY SAID SELECTIVELY ACTUABLE MEANS. 